A11y: Add/refactor methods for manipulating bitfields on AXNodeData.

ash/system/user/user_card_view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/user/user_card_view.h"
 
 #include <algorithm>
 #include <memory>
 #include <vector>
 
@@ skipping 306 matching lines @@
   std::vector<base::string16> labels;
 
   // Construct the name by concatenating descendants' names.
   std::list<views::View*> descendants;
   descendants.push_back(this);
   while (!descendants.empty()) {
     auto* view = descendants.front();
     descendants.pop_front();
     if (view != this) {
       ui::AXNodeData descendant_data;
+      descendant_data.ClearBitfields();
       view->GetAccessibleNodeData(&descendant_data);
       base::string16 label =
           descendant_data.GetString16Attribute(ui::AX_ATTR_NAME);
       // If we find a non-empty name, use that and don't descend further into
       // the tree.
       if (!label.empty()) {
         labels.push_back(label);
         continue;
       }
     }
@@ skipping 104 matching lines @@
   media_capture_container_ = new views::View();
   media_capture_container_->SetLayoutManager(new views::FillLayout());
   media_capture_container_->AddChildView(media_capture_icon_);
   AddChildView(media_capture_container_);
 
   Shell::Get()->media_controller()->RequestCaptureState();
 }
 
 }  // namespace tray
 }  // namespace ash